원래 이름 기록: Hitachi Vantara, Ltd.

A second storage device stores data of a clone volume in a pool of the second storage device, and when the data is not stored in the pool of the second storage device, acquires the data from a pool of a first storage device and stores the data in the pool of the second storage device, and enables data related to a primary volume stored in the pool of the second storage device to be commonly accessed by a plurality of the clone volumes.

A first data mapping table is specified such that each chunk in a first chunk group in each first arrangement group including the first chunk group is distributedly arranged in a different computer node, a second data mapping table is specified such that each chunk in a second chunk group in each second arrangement group including the second chunk group is distributedly arranged in a different computer node, and processor configured to determine whether an imbalance in unallocated capacity among the plurality of computer nodes is within a tolerance, allocate first chunk groups to unallocated capacity of computer node groups with use of the first data mapping table, for when the imbalance is outside the tolerance, and allocate second chunk groups to unallocated capacity of the plurality of computer nodes with use of the second data mapping table, for when the imbalance is within the tolerance.

A backup system includes a plurality of backup storage devices for storing backup data of backup target data stored in a storage device. The plurality of backup storage devices are classified as backup storage devices belonging to either a primary layer or a secondary layer. In the backup system, the backup target data is backed up by the storage device storing primary backup data, which is backup data of the backup target data, in the backup storage device belonging to the primary layer, and the backup storage device belonging to the primary layer storing secondary backup data, which is backup data of the primary backup data, in the backup storage device belonging to the secondary layer.

The present invention has been made to reduce influence of maintenance events on performance. Disclosed is a storage system that includes a plurality of storage nodes, each having an arithmetic device and a memory. Upon detecting a failure of a separate storage node in the storage system, the plurality of storage nodes take over the failed storage node by failover. When a maintenance event occurs in the storage system, the plurality of storage nodes change, according to maintenance event information, conditions for detecting the failure of a storage node related to the maintenance event, and restrict data input/output processing. The maintenance event information is the information regarding the maintenance event.

A first journal group including a primary volume and a first journal volume and a second journal group including a secondary volume and a second journal volume are set in a consistency holding group. Journal processing is performed while ensuring consistency of replication between the first journal group and the second journal group. The second journal group is arranged for each node in which the secondary volume of the consistency holding group is arranged. The secondary volume is arranged in each node in the second storage system based on a usage status of a resource of each node in the second storage system and the number of nodes in which the secondary volume in the consistency holding group is arranged.

A document search system stores a document search database indicating a content hierarchical structure of one or more documents. A document search system receives a search keyword input from a user, searches a document search database for items matching the search keyword, and determines a result item to be presented to the user from a plurality of items matching the search keyword by sequentially selecting items from a higher hierarchy to a lower hierarchy according to a content hierarchical structure including the plurality of items. The selection in at least one hierarchy follows selection by the user from a plurality of option items presented to the user.